There are a number of fasteners on the market for securing multiple structures together. In certain structural connections, however, it is important to provide an electrical connection or bond between the structures. This is particularly important in situations were a grounded condition is needed.
For example, in equipment enclosure racks, such as audio or computer equipment racks, grounding through multiple racks is generally required. Since many racks have a protective paint coating, the direct attachment using conventional nuts and bolts is not, in some cases, sufficient to provide an electrical connection. As such, in order to provide adequate grounding, separate grounding wires are typically used to provide electrical continuity. One end of the grounding wire is attached to a stud or post and the other end is attached to a grounding bus bar mounted to the rack. While this type of attachment is adequate for providing electrical grounding, the attachment of the grounding wires is time consuming and subject to error should the ground connection not be properly completed.
A product that was recently introduced by Panduit Corporation is referred to as the Tapped Rail Bonding Stud Kit and includes a nut and bolt arrangement with serrations or teeth formed integral to and on the bottom of the nut and bolt. That product is described in detail in U.S. Patent Publication No. 2006/0257229.
While the Panduit product does address the problem for breaking through the paint layer to reach the base metal, Applicant has determined that the product negatively impacts the appearance of the components and can create a corrosion source since the serrations are designed to remove a complete circular ring of paint exposing the bare metal. The ring of bare metal is susceptible to corrosion unless an anti-oxidant is applied. However, application of anti-oxidants is an additional assembly step and can be difficult to apply.